For example, there are given two types of a constant velocity universal joint, specifically, a fixed type constant velocity universal joint and a plunging type constant velocity universal joint to be used as means for transmitting rotational torque from an engine of an automobile to a wheel at a constant velocity. Both of the constant velocity universal joints have a structure in which two shafts, specifically, a shaft on a driving side and a shaft on a driven side are coupled to each other to allow rotational torque to be transmitted at a constant velocity even when the two shafts form an operating angle.
It is required that a drive shaft configured to transmit power from an engine of an automobile to a driving wheel support angular displacement and axial displacement caused by a change in relative positional relationship between the engine and the wheel. Therefore, in general, the drive shaft has the following structure. That is, the plunging type constant velocity universal joint is mounted on an engine side (inboard side), and the fixed type constant velocity universal joint is mounted on a driving wheel side (outboard side). Both of the constant velocity universal joints are coupled to each other through intermediation of a shaft.
In the plunging type constant velocity universal joint or the fixed type constant velocity universal joint, in order to prevent leakage of a lubricant sealed in the joint and entry of foreign matters from an outside of the joint, a boot is mounted between an outer joint member of the constant velocity universal joint and the shaft. This type of boot is fastened with a metallic boot band (see, for example, Patent Literature 1) to be fixed to the outer joint member and the shaft, thereby ensuring a sealing performance.
The boot band disclosed in Patent Literature 1 is of a type called a one-touch operation type. The boot band includes a band body and a lever. The band body is formed into a ring shape by joining both end portions of a band-plate-like member together. The lever is obtained by forming a strip-like member into an arc shape and is provided on a joined portion of the band body.
The boot band is assembled in the following manner. First, prior to assembly of the boot band, an end portion of the boot is mounted to the outer joint member of the constant velocity universal jointer the shaft. At this time, the boot band is arranged on an outer side of the end portion of the boot.
Under this state, in the boot band, the lever is turned over using a proximal end portion of the lever as a fulcrum, and then the lever is superposed on the band body. In this manner, the band body is reduced in diameter. With the boot band in which the band body is reduced in diameter, the end portion of the boot is fastened and fixed to the outer joint member of the constant velocity universal joint or the shaft.